1. Field of the Invention
The present invention generally relates to a touch panel, and more particularly to a touch sensitive in-plane switching (IPS) liquid crystal display (LCD).
2. Description of the Related Art
Touch panels and touch screens have been widely used in electronic devices, particularly portable and hand-held electronic devices such as personal digital assistants (PDA) and mobile telephones. Touch panels incorporate sensing technology (such as resistive, capacitive, or optical sensing technology) and display technology. Maturing liquid crystal display (LCD) developments further facilitate the integration of sensing technologies with the LCD.
FIG. 1 is a cross-sectional view showing the structure of a conventional touch sensitive LCD 9, as disclosed, for example, in U.S. Pat. No. 6,259,490 entitled “LIQUID CRYSTAL DISPLAY DEVICE” or U.S. Patent Application Publication No. 2007/0242054A1 entitled “LIGHT TRANSMISSION TOUCH PANEL AND MANUFACTURING METHOD THEREOF.” As shown in FIG. 1, the touch sensitive LCD 9 includes, from bottom to top, a thin-film transistor (TFT) substrate 1, a liquid crystal (LC) layer 2, a common electrode layer 3, a color resist (CR) layer 4, a color filter (CF) substrate 5, a sensing electrode layer 6, and a polarizing plate 7. According to the structure of the conventional touch sensitive LCD 9, in which both the common electrode layer 3 and the sensing electrode layer 6 are disposed above the LC layer 2, high background capacitance adversely affect the sensing electrode layer 6, thereby decreasing the performance and accuracy of the touch sensitive LCD 9. Furthermore, regarding the structure of the conventional touch sensitive LCD 9, an electric field of the LC layer 2 also adversely affects the touch performance and accuracy of the sensing electrode layer 6.
As the conventional touch sensitive LCD suffers from suboptimal sensing performance and accuracy, a need exists to propose a novel touch sensitive LCD that is capable of providing one or more of improved sensing performance and accuracy.